Fix bug introduced into indexable_outerrelids() by an ill-considered

tglsfdc · tglsfdc · commit d7e4fd99e53d · 2005-09-22T23:25:07.000Z
"optimization".  When we find a potentially useful joinclause, we
have to add all its other required_relids to the result, not only the
other clause_relids.  They are different in the case of a joinclause
whose applicability has to be postponed due to outer join.  We have
to include the extra rels because otherwise, after best_inner_indexscan
masks the join rels with index_outer_relids, it will always fail to
find the joinclause as applicable.  Per report from Husam Tomeh.
diff --git a/src/backend/optimizer/path/indxpath.c b/src/backend/optimizer/path/indxpath.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.188 2005/08/28 22:47:20 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.189 2005/09/22 23:25:07 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -955,15 +955,13 @@ indexable_outerrelids(RelOptInfo *rel)
 	/*
 	 * Examine each joinclause in the joininfo list to see if it matches any
 	 * key of any index.  If so, add the clause's other rels to the result.
-	 * (Note: we consider only actual participants, not extraneous rels
-	 * possibly mentioned in required_relids.)
 	 */
 	foreach(l, rel->joininfo)
 	{
 		RestrictInfo *joininfo = (RestrictInfo *) lfirst(l);
 		Relids	other_rels;
 
-		other_rels = bms_difference(joininfo->clause_relids, rel->relids);
+		other_rels = bms_difference(joininfo->required_relids, rel->relids);
 		if (matches_any_index(joininfo, rel, other_rels))
 			outer_relids = bms_join(outer_relids, other_rels);
 		else

Original file line number	Diff line number	Diff line change
`@@ -9,7 +9,7 @@`
`9`	`9`	`*`
`10`	`10`	`*`
`11`	`11`	`* IDENTIFICATION`
`12`		`- * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.188 2005/08/28 22:47:20 tgl Exp $`
	`12`	`+ * $PostgreSQL: pgsql/src/backend/optimizer/path/indxpath.c,v 1.189 2005/09/22 23:25:07 tgl Exp $`
`13`	`13`	`*`
`14`	`14`	`*-------------------------------------------------------------------------`
`15`	`15`	`*/`
`@@ -955,15 +955,13 @@ indexable_outerrelids(RelOptInfo *rel)`
`955`	`955`	`/*`
`956`	`956`	`* Examine each joinclause in the joininfo list to see if it matches any`
`957`	`957`	`* key of any index. If so, add the clause's other rels to the result.`
`958`		`- * (Note: we consider only actual participants, not extraneous rels`
`959`		`- * possibly mentioned in required_relids.)`
`960`	`958`	`*/`
`961`	`959`	`foreach(l, rel->joininfo)`
`962`	`960`	`{`
`963`	`961`	`RestrictInfo joininfo = (RestrictInfo ) lfirst(l);`
`964`	`962`	`Relids other_rels;`
`965`	`963`
`966`		`- other_rels = bms_difference(joininfo->clause_relids, rel->relids);`
	`964`	`+ other_rels = bms_difference(joininfo->required_relids, rel->relids);`
`967`	`965`	`if (matches_any_index(joininfo, rel, other_rels))`
`968`	`966`	`outer_relids = bms_join(outer_relids, other_rels);`
`969`	`967`	`else`